The Mark of the Beast is a seal or sign given to by the Antichrist. It is said that the Beast of the Earth was given power to give breath to the image of the first beast, whom is the Beast of the Sea, so that the image could speak and cause all who refused to worship the image to be killed.
The Beast then ventured around the globe and began to force all people, whether great and small, rich and poor, free and slave, to receive a mark on their right hands or on their foreheads, so that they could not buy or sell unless they had the mark, which is the name of the beast or the number of its name. It is believed that the number of the Beast is 666.
Those whom have recieved the mark of the Beast are forever damned in pits of sulfur and brimstone and do not follow God. For those who have taken the mark are followers of the Beast, and even if they do not want to follow the Beast, they will unable to fight an urge to battle alongside the monster.